Various structures are provided with pipe systems, such as vent pipe systems, which lead from inside the structure to terminate at point outside an external surface of the structure for venting purposes. For example, every home with indoor plumbing has a vent component that allows atmospheric air to enter the plumbing drain system. Today, this vent is most commonly made of standard Schedule 40 DWV PVC pipe and is established in a vertical manner penetrating through the roof of the home. However, historically the vent pipe was formed by a mixture of differing pipe materials, some were of cast iron, some were of iron pipe material and some were of copper pipe material. Hence, a given home built within the last twenty years or so will most likely have a schedule 40 PVC vent pipe, although copper may have been used on some architecturally specified higher-end homes; while homes older than this may have a vent pipe of cast iron, iron, or copper. In addition, the number and size(s) of the vent pipe(s) is/are typically determined during construction by the plumber or other professional in accordance with applicable national, state, and local regulatory requirements like building/plumbing codes. These vent pipes may typically be as small as 1¼″ pipe or as large as 4″ pipe depending on the particular plumbing system within the home. Common vent pipe sizes for example include 1¼″, 1½″, 2″, 3″ and 4″ Schedule 40 PVC DWV.
Since this vent pipe component penetrates the roof structure and the water shedding covering (such as roof shingles), a flashing seal must be used to insure the water-tight integrity of the roof system. Roof covering installers are typically tasked with the installation of these flashing seal components during the installation of the roof covering materials. Since the vent pipe element may be made from one of several materials and may be one of several sizes for any particular home, a roof contractor will need to be ready to address the flashing seal to any one of these vent pipe situations (for example, 4 materials and 5 potential pipe sizes=20 different combinations that may be present on any given roof system).
Roof penetrations are sealed with flashings to prevent the ingress of moisture into the attic spaces of a residence or commercial building. Often, these penetrations are provided to accommodate pipes for venting plumbing systems within the building or structure. These pipes are vertically oriented and are often of standard Schedule 40 PVC DWV pipe material which is commonly a white color. As noted, prior to the use of PVC for plumbing pipe applications, other materials were used to manufacture the pipe. Cast iron and copper were the two main materials used for vent pipe manufacture prior to the introduction of PVC; as such there remains a multitude of buildings with existing plumbing infrastructure of cast iron and copper. The cast iron pipes will most often have a surface which is pitted and rough; and, many times, previous flashing seals were applied with various caulks, mastics, or tar; which leaves remnant material that becomes hardened to the exterior of the pipe. A copper pipe tends to oxidize and thin-out due to acid rain and other long-term weathering effects. A copper pipe will also be found with remnants of mastic, caulk and sealants hardened to the exterior.
Since these cast iron and copper vent pipes have been in-use for many years, they may have seen several roof covering replacement events. With each roof covering replacement the vent pipe is once again sealed in an effort to prevent moisture intrusion. In most instances of these older vent pipe installations the flashing seal has been covered with roof cement, sealant of one form or another or just plain tar; leaving the exterior surfaces covered with an array of old hardened adhesives as well as years of accumulated debris. These old crusty coated surfaces are difficult to work with and cause much frustration when trying to clean so as to provide an adequate sealing surface for a new flashing.
Attaining a water-tight seal to the oxidized, rough, pitted, and irregular surface of an existing pipe, other than PVC is difficult at best and sometimes practically impossible. Current remedies for this situation include accessing the pipe within the attic space under the roof and splicing a new piece of pipe into the existing system. This operation is expensive, time consuming and often extremely difficult, as the vent pipes are located in an inaccessible portion of the attic space.
Hence, there exists a need to assist the contractor with a means to repair the old crusty vent pipe penetrations and allow a flashing to be installed to provide adequate sealing for protection against the intrusion of moisture into the building or residence.